Method of making a hot top



Feb. 11, 1964 2 Sheets-Sheet Filed March 17. 1959 INVENTOR MARK /v $2; U266 lrne Feb. 11, 1964 M. H. GATHMANN ,1

METHOD OF MAKING A HOT TOP Filed March 17, 1959 2 Sheets-Sheet 2 INVENTOR MARK H. 6A 7' HMA/V/V A Home 3,129,684 METHDD OF MAKING A HOT TOP Mark H. Gathrnann, Chicago, Ill., assignor to United States Steel Corporation, a corporation of New Jersey Filed Mar. 17, 1959, Set. No. 799,933 3 Claims. (Cl. 22-192) This invention relates to a method of making a hot top, and more particularly to a hot top including a casing of cast iron or cast steel. Hot tops of this general type usually have a thick refractory lining and a thin parting compound on the refractory lining. The vertical openings in the hot top generally increase in cross-section from the top to the bottom thereof in a uniform manner. Most of the hot tops are so constructed that there is a relatively wide shoulder between the poured metal in the hot top and the poured metal in the ingot mold proper. This shoulder on the ingot results in overlapping of metal during the rolling of the ingot.

It is therefore an object of my invention to provide a method of making a hot top which is so shaped that a narrower shoulder is provided between the ingot proper and the metal in the hot top.

Another object is to provide a method of making a hot top in which the usual thick refractory lining on the metal casing is eliminated.

These and other objects will be more apparent after referring to the following specification and attached drawings, in which:

FIGURE 1 is a vertical sectional view showing a hot top of my invention in place on an ingot mold;

FIGURE 2 is a top plan View showing a second embodiment of my invention;

FIGURE 3 is a sectional view taken on the line IIIIII of FIGURE 2;

FIGURE 3a is an enlarged view of a detail of FIG- URE 3; and

FIGURE 4 is a View, similar to FIGURE 1, showing a third embodiment of my invention.

Referring more particularly to FIGURE 1 of the drawings, reference numeral 2 indicates an ingot mold having the usual opening 4 therein. The hot top of my invention consists of a cast metal casing 6 having a generally vertical opening 8 therethrough with a refractory lining 10 on the walls of the opening 8. The upper portion 12 of opening 8 is of generally uniform cross section, but is preferably slightly tapered from the top downwardly and outwardly to a point intermediate its height so as to facilitate stripping and providing contact for the stripper and soaking pit tongs. The walls of the opening 8 then taper sharply downwardly and outwardly at 14 to a point a short distance above the bottom of the metal casing 6. The walls then extend downwardly substantially vertically to the bottom of the casing. The taper 14 could be concave or convex instead of straight as shown. The metal casing 6 is preferably provided with an air chamber 16 for insulating purposes. The lining 10 is preferably sand or other refractory with a resinous binder. If desired an exothermic material may be added to the mix to increase the time required for solidification of the metal in the hot top. It will be seen that the enlarged lower portion of the hot top results in a narrow shoulder between the portion of the ingot in the mold proper and that in the hot top. When the hot steel is poured into the mold and rises in the hot top the lining 10 will disintegrate to a fine powdered ash forming a void between the casing 6 United States Patent "ice and the hot top section of the ingot. The refractory lining 19 also prevents welding or adhesion of the ingot to the walls of the opening 8.

In preparing the hot top for use, the metal casing 6 is heated to a temperature of between 250 and 800 F. This may be done as a separate operation, but it is pre ferred that the casing be prepared while it is still hot from the previous cast. It is preferred to mix sand with a resinous binder and either with or without an exothermic material and then blow or spray the particles on the walls of the opening 8 while the metal casing is at a temperature of between 400 and 800 F. The refractory could also be applied in the form of a slurry while the metal casing 6 is at a temperature of between 250 and 400 F.

FIGURES 2, 3 and 3a show a second embodiment of my invention which is quite similar to that of FIGURE 1. In this embodiment a metal casing 18 is provided with a vertical opening Ztl, the upper portion 22 of which slopes downwardly and outwardly in the same manner as the upper portion of metal casing 6. The lower portion 24 of the opening slopes or tapers downwardly and outwardly to the bottom of the casing. An opening 26 is provided in the metal casing 18 for insulation'purposes and a lining 28 is provided for the opening 20. The lining 23 may be a sheet metal sleeve, a lining similar to that of FIGURE 1, or a sheet metal sleeve with a refractory bonded thereto as shown. A refractory bottom ring 30 and metal wiper strip 32 are attached to the bottom of the casing 15% in any suitable manner. The thickness of the refractory lining is preferably between A; and /2 inch. It will be seen that this hot top, like that of FIGURE 1, results in a very narrow shoulder on the ingot.

In the embodiment of my invention shown in FIGURE 4, a metal casing 34 rests on top of the mold 2. In addition to having a cored opening 36 therein and a vertical opening 38 therethrough the casing has a plurality of horizontal holes or slots 40 spaced vertically apart in the walls of opening 38. A metal sleeve 42 having a refractory liner 44 is placed in the opening 38. This liner may have the same composition and may be applied in the same manner as that of FIGURE 1. Horizontal holes or slots 45 are provided through the sleeve 42 and refractory liner 44. Wooden pegs or keys 48 passing through the holes 46 into the holes 40 hold the sleeve 42 in position. The amount that the sleeve extends into the open ing 4 may be varied by placing the pins 48 in holes 46 at different levels.

While several embodiments of my invention have been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. The method of making a hot top comprising providing a metal casing having a generally vertical opening therethrough, heating the metal casing, and placing a refractory lining having a resinous binder on the walls of said opening to a maximum thickness of /2 inch while the metal temperature is between 250 and 800 F. whereby the refractory and binder are bonded to said metal casing.

2. The method of making a hot top comprising providing a metal casing having a generally vertical opening therethrough, heating the metal casing, and placing a refractory slurry having a resinous binder on the walls of said opening to a maximum thickness of /2 inch while the metal temperature is between 250 and 400 F. where- 3 4 by the refractory and binder are bonded to said metal References Cited in the file of this patent casing.

3. The method of making a hot top comprising pro- UNITED STATES PATENTS viding a metal casing having a generally vertical opening 1,803,342 Messler et a1. May 5, 1931 therethrough, heating the metal casing, and spraying par- 5 1,921,729 Charman Aug. 8, 1933 ticles of refractory having a resinous binder on the walls 2,147,147 Charman Feb. 14, 1939 of said opening to a maximum thickness of /2 inch While 2,861,305 Fenton Nov. 25, 1958 the metal temperature is between 400 and 800 P. where- 2,869,191 Cooper et al Jan. 20, 1959 by the refractory and binder are bonded to said metal cas- 2,869,196 Cooper et a1. J an. 20, 1959 ing, 10 

1. THE METHOD OF MAKING A HOT TOP COMPRISING PROVIDING A METAL CASING HAVING A GENERALLY VERTICAL OPENING THERETHROUGH, HEATING THE METAL CASING, AND PLACING A REFRACTORY LINING HAVING A RESINOUS BINDER ON THE WALLS OF SAID OPENING TO A MAXIMUM THICKNESS OF 1/2 INCH WHILE THE METAL TEMPERATURE IS BETWEEN 250 AND 800*F. WHEREBY THE REFRACTORY AND BINDER ARE BONDED TO SAID METAL CASING. 